Catalysis of Positively Charged Ru Species Stabilized by Hydroxyapatite in Amine Formylation

Graphical Synthetic methods : We designed a hydroxyapatite (HAP)-stabilized, positively charged Ru-based catalyst which can efficiently catalyze the formylation reaction of amines with CO for the synthesis of formamide. The combination of characterization results and control experiments showed that positively charged Ru species, particularly the hydrated RuO x particles on the surface were essential to the high catalytic activity of Ru-HAP in the formylation reaction. Formamide is an important solvent and synthetic intermediate. Herein, we designed a hydroxyapatite (HAP)-stabilized, positively charged Ru-based catalysts which can efficiently catalyze the formylation reaction of amines with CO for the synthesis of formamide. The Ru-HAP showed excellent catalytic performance in N,N-Dimethylformamide (DMF) synthesis, with about 75 % dimethylamine conversion and >99 % DMF selectivity at 300 h of continuous reaction. The combination of characterization results and control experiments showed that positively charged Ru species, including hydrated RuO x and Ru 3+ species, were catalytically active. In particular, the surface RuO x species were more active than the Ru 3+ species located within the HAP framework.